摘要
研究了350℃热轧和室温冷轧对8090合金超塑性的影响。变形结果表明,热轧态的8090 合金的最佳延伸率为530％,而冷轧的达到630％。透射电镜观察及晶界角度测量结果表明,冷轧试样获得了较小尺寸的位错胞,在超塑变形初期冷轧试样中的应变诱发再结晶比热轧的快。在δ=25％时,冷轧试样的大角度晶界(≥10°)分数为0.67。而热轧的只有0.48。研究指出,应变诱发再结晶对细化晶粒和提高大角度晶界分数的作用明显地影响合金的超塑性能。
The influences of rolling processes at 350℃ and room temperature on superplasticity of 8090 Al-Li alloy were investigated. The results showed that the optimum elongation is 550%, by hot rolling but 630% by cold rolling. TEM observation and measurement of grain boundary angle indicated that.compared with hot rolling.cold rolled specimens can get smaller dislocation cell size and more rapid recrystallization induced by strain. When δ = 25% .the high-angle grain boundary fraction is up to 0. 67 in cold rolled specimens(≥10°) but only 0. 48 in hot rolled ones. It is evident that the effects of strain-induced recrystallization on grain refining and on high-angle grain boundary fraction increasing affect greatly the superplastic properties of the alloy.
基金
国家教委博士点基金
关键词
再结晶
铝锂合金
超塑性
轧制工艺
strain-induced recrystallization
Al-Li alloy
superplasticity
